Subtraction
1st Grade - Subtraction Teaching Point/Goal: *Students will be able to solve subtraction word problems by using the problem-solving strategy of drawing pictures. Framing Questions: ''Questions that teacher and students will consider throughout the lesson.'' ''' *What steps should you follow to solve a problem? *How can we solve subtraction problems by drawing pictures? Does illustrating a problem help us check our answers? *Is there a relationship between addition and subtraction? How can counting help us solve subtraction problems? '''Link To Standards: ''What competencies from the NYC/NYS Common Core Standards are addressed in this lesson? '' Represent and solve problems involving addition and subtraction. *1. OA 1. Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem. ' ' Add and subtract within 20. *1. OA 5. Relate counting to addition and subtraction (e.g., by counting on 2 to add 2). ' ' Performance Indicators: ''' *Students will be able to identify the part of a story problem that needs to be solved. *Students will be able to solve subtraction problems within 20. *Students will be able to show how they solved the problems using pictures. ' ' ' '''Connection/Motivation: ' The students have just begun a month-long unit on Subtraction. This lesson will build off of some of the concepts already introduced, which included using counters and other manipulatives to solve story sentences. The teacher will begin lesson by reading the teaching point posted on the Smartboard. The teacher will review some of the subtraction strategies that they’ve already learned, including using a number line and also counters. The teacher will model a question covered in a previous lesson (5 -2 = 3). The teacher will tell students that they are going to use the book The Action of Subtraction to learn about solving subtraction problems with pictures. ' ' Lesson Development: ' '''Model (I try): ' The teacher will read a few pages from the book. The teacher will pause to point out how that author represented subtraction problems by using different pictures. The teacher will then show one of the story problems from the book (p.8) on the Smartboard. The teacher will rewrite it in the form of a question. “There are 7 angry bulldogs barking at your door. A kitten scares away 3. How many bulldogs are left?” The teacher will explain that the first step to solve this story problem is to determine what the question is. The teacher will then circle the appropriate part. The teacher will then explain that it can be helpful to draw a picture to solve this problem. The teacher will demonstrate this by first drawing a quick sketch of the total amount of dogs at the beginning (7). The teacher will point out, “Unlike the author of this book, I am not a professional artist. To solve this problem, I am not going to try and draw perfect looking bulldogs. Rather, I am just going to draw a circle with four legs to represent the dogs. I am creating a Math Picture that helps me solve the problem.” The teacher will then demonstrate the process of subtraction by crossing out 3 of the dogs (scared away by the kitten). The teacher will then count the number of bulldogs that remain and write the answer on the Smartboard. The teacher will point out that drawing pictures can also help us check our answers through addition. Since adding the amount of bulldogs that remain to those that were scared away should equal to 7 bulldogs total. If we count more or less than 7 total dogs then we know we got the wrong answer. 'Active Involvement (We try): ' The teacher will then revisit another scenario from the book. It will be re-written in the form of a story problem and posted on the Smartboard. The teacher will ask the students, “What do I need to find out? If we want to circle the question, what would we circle?” A student will then be invited to circle the appropriate part on the Smartboard. The students will do a turn-and-talk and discuss with a partner how they would use pictures to solve the problem. A student volunteer will be invited to the front to solve the problem by drawing a picture. The first picture should be of the total amount of objects and then the student should cross out the subtracted amount. The teacher will ask, “Is this the only type of picture we can draw to solve the problem?” After a few more students reply, the teacher will point out/remind them that you don’t have to draw perfect pictures. Drawing circles or shapes to represent the object is fine. The teacher will tell students, “If you are having trouble solving a problem, you can use counters and cubes. You can also draw a picture of these counters and cubes to illustrate your subtraction story problem.” 'Independent/partner activity/group activity (You try): ' The teacher will then explain the independent activity to the students. The teacher will post instructions on the Smartboard and also have a student tell back the instructions. Students will go back to the tables to complete the worksheets (A) on their own. The students will have to solve several story problems using the draw a picture problem-solving strategy. First, students will need to read the story problem. Then they will circle the question. Next they will draw a picture to represent the problem. Lastly, they will write their answer. The teacher will circulate to different tables to assist and answer student’s questions. Students that finish early will be given an additional worksheet (B) where they can make up their own story problems to solve. '''Plan for Differentiated Instruction/Activity: ''What modifications will you use to meet the needs of all students? '' · Students who are unsure of directions can remain on the rug with the teacher to get help with the first problem. · The teacher will provide individual support to students who have trouble reading the story problems. · If students complete the first worksheet (A), they will be given a second worksheet (B) where they can come up with the values in a story problem, as well create their own question to solve. · Each table will also be given different manipulatives (such as counters, unifix cubes, etc.) which they can use to help solve the problems and draw their pictures. ' ' 'Share/Closure: ' Students will reconvene on the carpet. The teacher will go over 1 to 2 problems from the Worksheet A. The teacher will have a student explain how he or she solved the problem and share the picture they drew. The teacher will then have several students share the story problems they created and solved from Worksheet B. Teacher will review how pictures can be used as a problem-solving strategy for subtraction. Section heading Write the first section of your page here. Section heading Write the second section of your page here. Category:Math